多梁式钢—混凝土组合小箱梁桥受力特性及试验研究

发布时间：2018-05-03 12:52

本文选题：多梁式钢-混组合小箱梁桥 + 混杂纤维混凝土　；参考：《浙江大学》2014年博士论文

【摘要】：近年来,钢-混组合结构在桥梁工程领域中逐步被使用,但对有关多梁式钢-混组合小箱梁桥的研究甚少,现行钢-混组合结构设计规范也未就其作出具体规定。为此本文对多梁式钢-混组合小箱梁桥的受力特性及行为进行研究,以为其在今后设计和运营后的管养提供参考。首先通过对十四个推出试件及两片组合箱梁模型的静载试验、数值模拟及国内外规范的对比,研究钢-混杂纤维混凝土组合梁的力学特性,给出了混杂纤维混凝土焊钉剪力件的荷载-滑曲线表达式及极限承载力计算方法,探讨了钢-混杂纤维混凝土组合箱梁在弹性状态和破坏状态的力学行为,并对钢-混杂纤维混凝土组合箱梁极限承载力的设计方法提出了建议。同时,试验研究和理论分析结果表明钢-混杂纤维混凝土组合箱梁在韧性和抗裂性等方面力学性能更优越于普通混凝土组合箱梁。其次,基于Newmark组合梁滑移模型,通过引入不同次幂抛物线翘曲函数来描述组合箱梁顶底板应力横向非均匀分布,建立一个能够同时考虑界面滑移、剪切变形和翼板剪力滞三重效应的钢混组合箱梁模型,推导了简支组合箱梁在均布荷载和集中荷载作用下的解析解。参数分析表明,随着混凝土板厚和钢梁高度的增加,在跨中腹板和顶板中部处剪力滞系数下降；当组合箱梁宽跨比减少时,在腹板处剪力滞系数下降,而在顶板中部处剪力滞系数略增加；与均布荷载相比,各因素变化在集中荷载作用下,对组合箱梁跨中截面的剪力滞系数影响较明显；滑移刚度变化对剪力滞系数的影响可以忽略不计。在上述理论分析及设计加工的试验模型基础上,进一步对典型的两片组合箱梁模型进行了剪滞试验研究,结果表明,理论分析与试验测试结果吻合很好,验证了理论模型和解析解的正确性。从实用设计方法出发,考虑多梁式钢-混组合小箱梁桥界面滑移效应,分别用传统的多梁式桥的偏心压力法、刚接梁法,推导了考虑界面滑移效应影响的偏心压力法、刚接梁法修正计算公式。通过实际工程算例表明,采用本文所提出的修正理论算法结果与有限元方法的计算结果吻合较好,表明所提出的修正刚接梁法适用于计算多梁式钢-混组合小箱梁桥跨中横向分布系数,当满足窄桥条件时,也可采用考虑滑移的修正偏心压力法。参数研究表明,在进行多梁式钢-混组合小箱梁桥设计时,为减少桥梁的偏载效应,建议采用不完全剪力连接形式。最后,基于比拟板法,在竖向荷载作用下具有多道横隔梁的多梁式钢混组合小箱梁桥通过纵横向刚度离散,同时考虑混凝土与钢梁间焊钉的滑移影响,将其比拟成一个正交异性板,利用薄板理论建立了多梁式钢混组合小箱梁桥整体分析的微分方程组,简化后求出在均布荷载下的滑移方程和挠度方程。通过算例与有限元数值结果及已有研究进行比较,验证其正确性。结果表明,剪力连接件的刚度变化对组合梁挠度影响可以忽略,而对滑移量影响较为明显。
[Abstract]:In recent years, the steel-concrete composite structure has been gradually used in the field of bridge engineering, but there is little research on the multi beam steel mixed combination small box girder bridge, and the current steel mixed composite structure design specification has not been specified. Provide reference for the future design and operation of management.
In this paper, the mechanical properties of steel hybrid fiber reinforced concrete composite beams are studied by static load test, numerical simulation and domestic and foreign norms, and the calculation method of load slip curve and ultimate bearing capacity of hybrid fiber reinforced concrete shear parts are given through the static load test, numerical simulation and domestic and foreign norms, and the steel mixing is discussed. The mechanical behavior of the fiber reinforced concrete composite box beam in the elastic state and failure state and the design method of the ultimate bearing capacity of the steel hybrid fiber concrete composite box girder are proposed. At the same time, the experimental and theoretical analysis results show that the mechanical properties of the steel hybrid fiber concrete composite box are superior to the mechanical properties of Liang Zairen and crack resistance. General concrete composite box girder.
Secondly, based on the Newmark composite beam slip model, by introducing different power parabolic warpage functions to describe the transverse non uniform distribution of stress in the top and bottom of the composite box beam, a steel mixed box girder model which can simultaneously consider the three effects of interface slip, shear deformation and shear lag of wing plate is established, and the simple supported composite box girder is derived in the uniform load. The analysis shows that the shear lag coefficient decreases with the increase of the thickness of the concrete plate and the height of the steel beam. When the Liang Kuan span ratio decreases, the shear lag coefficient at the web is reduced, and the shear lag coefficient at the middle of the top plate is slightly increased; compared with the uniform load load, the shear lag coefficient is slightly increased. The influence of various factors on the shear lag coefficient of the middle cross section of the composite box girder is obvious under the concentrated load, and the effect of the change of slip stiffness on the shear lag coefficient can be ignored. On the basis of the theoretical analysis and the experimental model of the design and processing, the shear lag test of the typical two composite box girder models is further studied. The results show that the theoretical analysis is in good agreement with the test results, and the correctness of the theoretical model and the analytical solution is verified.
From the practical design method, the slip effect of the multi beam steel and mixed composite small box girder bridge is considered. The eccentric pressure method of the traditional multi beam bridge and the rigid connection method are used respectively. The eccentric pressure method considering the effect of the interface slip effect and the correction formula of the rigid connection beam method are derived. The correction method proposed in this paper is shown by the practical engineering example. The results of the theoretical algorithm are in good agreement with the calculation results of the finite element method. It shows that the proposed modified rigid joint beam method is suitable for calculating the transverse distribution coefficient in the span of the multi beam steel mixed composite small box girder bridge. When the narrow bridge condition is satisfied, the modified eccentric pressure method considering slip can also be adopted. In the design of small box girder bridge, incomplete shear connection is recommended to reduce the partial load effect of the bridge.
Finally, based on the analogy plate method, the multi beam steel mixed composite small box girder bridge with multi beam cross beam is discrete through the longitudinal and transverse stiffness under the vertical load, and takes into account the slippage effect between the concrete and the steel beam, and compares it into a orthotropic plate, and the integral analysis of the multi beam steel mixed composite small box girder bridge is established by the thin plate theory. The differential equations of differential equations are simplified and the slip equation and deflection equation are obtained under uniform load. A numerical example is compared with the finite element numerical results and previous studies to verify its correctness. The results show that the stiffness change of the shear connectors can be neglected and the effect on the slip is more obvious.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U441;U446

【参考文献】